| Message ID | 20250226024338.3994701-3-quic_sibis@quicinc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | firmware: arm_scmi: Misc Fixes | expand |
On Wed, Feb 26, 2025 at 08:13:38AM +0530, Sibi Sankar wrote: > The addition of per message-id fastchannel support check exposed > a SCP firmware bug which leads to a device crash on X1E platforms. You're fixing a bug that is introduced in patch 1. That's not allowed. These need to be squashed into one patch. I means the patch will be slightly long and the commit message will be slightly long but I feel like it's manageable. > The X1E firmware supports fastchannel on LEVEL_GET but fails to > have this set in the protocol message attributes and the fallback > to regular messaging leads to a device crash since that implementation > has a bug for all the X1E devices in the wild. Fix this by introducing > a quirk that selectively skips the per message-id fastchannel check only > for the LEVEL_GET message on X1E platforms. > > Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com> > --- > drivers/firmware/arm_scmi/driver.c | 5 +++-- > drivers/firmware/arm_scmi/perf.c | 30 +++++++++++++++++++++------ > drivers/firmware/arm_scmi/powercap.c | 8 +++---- > drivers/firmware/arm_scmi/protocols.h | 2 +- > 4 files changed, 32 insertions(+), 13 deletions(-) > > diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c > index 9313b9020fc1..b182fa8e8ccb 100644 > --- a/drivers/firmware/arm_scmi/driver.c > +++ b/drivers/firmware/arm_scmi/driver.c > @@ -1903,7 +1903,8 @@ static void > scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, > u8 describe_id, u32 message_id, u32 valid_size, > u32 domain, void __iomem **p_addr, > - struct scmi_fc_db_info **p_db, u32 *rate_limit) > + struct scmi_fc_db_info **p_db, u32 *rate_limit, > + bool skip_check) > { > int ret; > u32 flags; > @@ -1919,7 +1920,7 @@ scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, > > /* Check if the MSG_ID supports fastchannel */ > ret = scmi_protocol_msg_check(ph, message_id, &attributes); > - if (!ret && !MSG_SUPPORTS_FASTCHANNEL(attributes)) > + if (!ret && !MSG_SUPPORTS_FASTCHANNEL(attributes) && !skip_check) > return; This is explained well in the commit message but the comment here needs to be better. Also if scmi_protocol_msg_check() fails then we should return. Let's rename the variable to "force_fastchannel". ret = scmi_protocol_msg_check(ph, message_id, &attributes); if (ret) return; /* * Check if the MSG_ID supports fastchannel. The force_fastchannel * quirk is necessary to work around a firmware bug. We can probably * remove that quirk in 2030. */ if (!force_fastchannel && !MSG_SUPPORTS_FASTCHANNEL(attributes)) return; > > if (!p_addr) { > diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c > index c7e5a34b254b..5b4559d0b054 100644 > --- a/drivers/firmware/arm_scmi/perf.c > +++ b/drivers/firmware/arm_scmi/perf.c > @@ -48,6 +48,10 @@ enum { > PERF_FC_MAX, > }; > > +enum { > + PERF_QUIRK_SKIP_FASTCHANNEL_LEVEL_GET, > +}; Let's keep the FORCE_FASTCHANNEL naming. Normally we would do this like: #define PERF_QUIRK_FORCE_FASTCHANNEL BIT(0) > + > struct scmi_opp { > u32 perf; > u32 power; > @@ -183,6 +187,7 @@ struct scmi_perf_info { > enum scmi_power_scale power_scale; > u64 stats_addr; > u32 stats_size; > + u32 quirks; > bool notify_lvl_cmd; > bool notify_lim_cmd; > struct perf_dom_info *dom_info; > @@ -838,9 +843,10 @@ static int scmi_perf_level_limits_notify(const struct scmi_protocol_handle *ph, > } > > static void scmi_perf_domain_init_fc(const struct scmi_protocol_handle *ph, > - struct perf_dom_info *dom) > + struct perf_dom_info *dom, u32 quirks) > { > struct scmi_fc_info *fc; > + bool quirk_level_get = !!(quirks & BIT(PERF_QUIRK_SKIP_FASTCHANNEL_LEVEL_GET)); bool force_fastchannel = !!(quirks & PERF_QUIRK_FORCE_FASTCHANNEL); > > fc = devm_kcalloc(ph->dev, PERF_FC_MAX, sizeof(*fc), GFP_KERNEL); > if (!fc) regards, dan carpenter
On Wed, Feb 26, 2025 at 08:13:38AM +0530, Sibi Sankar wrote: > The addition of per message-id fastchannel support check exposed > a SCP firmware bug which leads to a device crash on X1E platforms. > The X1E firmware supports fastchannel on LEVEL_GET but fails to > have this set in the protocol message attributes and the fallback > to regular messaging leads to a device crash since that implementation > has a bug for all the X1E devices in the wild. Fix this by introducing > a quirk that selectively skips the per message-id fastchannel check only > for the LEVEL_GET message on X1E platforms. > > Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com> > --- > drivers/firmware/arm_scmi/driver.c | 5 +++-- > drivers/firmware/arm_scmi/perf.c | 30 +++++++++++++++++++++------ > drivers/firmware/arm_scmi/powercap.c | 8 +++---- > drivers/firmware/arm_scmi/protocols.h | 2 +- > 4 files changed, 32 insertions(+), 13 deletions(-) > > diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c > index 9313b9020fc1..b182fa8e8ccb 100644 > --- a/drivers/firmware/arm_scmi/driver.c > +++ b/drivers/firmware/arm_scmi/driver.c > @@ -1903,7 +1903,8 @@ static void > scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, > u8 describe_id, u32 message_id, u32 valid_size, > u32 domain, void __iomem **p_addr, > - struct scmi_fc_db_info **p_db, u32 *rate_limit) > + struct scmi_fc_db_info **p_db, u32 *rate_limit, > + bool skip_check) This does not look like it will scale. > { > int ret; > u32 flags; > @@ -1919,7 +1920,7 @@ scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, > > /* Check if the MSG_ID supports fastchannel */ > ret = scmi_protocol_msg_check(ph, message_id, &attributes); > - if (!ret && !MSG_SUPPORTS_FASTCHANNEL(attributes)) > + if (!ret && !MSG_SUPPORTS_FASTCHANNEL(attributes) && !skip_check) Why can't you just make sure that the bit is set in attributes as I suggested? That seems like it should allow for a minimal implementation of this. > return; > > if (!p_addr) { > @@ -1282,6 +1288,7 @@ static int scmi_perf_protocol_init(const struct scmi_protocol_handle *ph) > { > int domain, ret; > u32 version; > + struct device_node *np; > struct scmi_perf_info *pinfo; > > ret = ph->xops->version_get(ph, &version); > @@ -1297,6 +1304,17 @@ static int scmi_perf_protocol_init(const struct scmi_protocol_handle *ph) > > pinfo->version = version; > > + /* > + * Some X1E devices support fastchannel for LEVEL_GET but erroneously > + * says otherwise in the protocol message attributes. Add a quirk to > + * force fastchannel on LEVEL_GET to prevent crashes on such devices. > + */ > + np = of_find_compatible_node(NULL, NULL, "qcom,x1e80100"); Here you should use of_machine_is_compatible(). > + if (np) { > + pinfo->quirks = BIT(PERF_QUIRK_SKIP_FASTCHANNEL_LEVEL_GET); > + of_node_put(np); > + } > + > ret = scmi_perf_attributes_get(ph, pinfo); > if (ret) > return ret; Johan
On Wed, Feb 26, 2025 at 09:12:23AM +0100, Johan Hovold wrote: > On Wed, Feb 26, 2025 at 08:13:38AM +0530, Sibi Sankar wrote: > > scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, > > u8 describe_id, u32 message_id, u32 valid_size, > > u32 domain, void __iomem **p_addr, > > - struct scmi_fc_db_info **p_db, u32 *rate_limit) > > + struct scmi_fc_db_info **p_db, u32 *rate_limit, > > + bool skip_check) > > This does not look like it will scale. After taking a closer look, perhaps it needs to be done along these lines. But calling the parameter 'force' or similar as Dan suggested should make it more readable. > > > { > > int ret; > > u32 flags; > > @@ -1919,7 +1920,7 @@ scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, > > > > /* Check if the MSG_ID supports fastchannel */ > > ret = scmi_protocol_msg_check(ph, message_id, &attributes); > > - if (!ret && !MSG_SUPPORTS_FASTCHANNEL(attributes)) > > + if (!ret && !MSG_SUPPORTS_FASTCHANNEL(attributes) && !skip_check) > > Why can't you just make sure that the bit is set in attributes as I > suggested? That seems like it should allow for a minimal implementation > of this. My idea here was that you could come up with some way of abstracting this so that you did not have to update every call site. Not sure how feasible that is. > > return; > > > > if (!p_addr) { Johan
On Wed, Feb 26, 2025 at 09:55:21AM +0100, Johan Hovold wrote: > On Wed, Feb 26, 2025 at 09:12:23AM +0100, Johan Hovold wrote: > > On Wed, Feb 26, 2025 at 08:13:38AM +0530, Sibi Sankar wrote: > > > > scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, > > > u8 describe_id, u32 message_id, u32 valid_size, > > > u32 domain, void __iomem **p_addr, > > > - struct scmi_fc_db_info **p_db, u32 *rate_limit) > > > + struct scmi_fc_db_info **p_db, u32 *rate_limit, > > > + bool skip_check) > > > > This does not look like it will scale. > > After taking a closer look, perhaps it needs to be done along these > lines. > > But calling the parameter 'force' or similar as Dan suggested should > make it more readable. > > > > > > { > > > int ret; > > > u32 flags; > > > @@ -1919,7 +1920,7 @@ scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, > > > > > > /* Check if the MSG_ID supports fastchannel */ > > > ret = scmi_protocol_msg_check(ph, message_id, &attributes); > > > - if (!ret && !MSG_SUPPORTS_FASTCHANNEL(attributes)) > > > + if (!ret && !MSG_SUPPORTS_FASTCHANNEL(attributes) && !skip_check) > > > > Why can't you just make sure that the bit is set in attributes as I > > suggested? That seems like it should allow for a minimal implementation > > of this. > > My idea here was that you could come up with some way of abstracting > this so that you did not have to update every call site. Not sure how > feasible that is. > I'm having a hard time finding your email. Why does the scmi_proto_helpers_ops struct even exist? We could just call all these functions directly. Do we have plans to actually create different implementations? If we got rid of the scmi_proto_helpers_ops struct then we could just rename scmi_common_fastchannel_init() to __scmi_common_fastchannel_init() and create a default wrapper around it and a _forced() wrapper. Some other potentially stupid ideas in the spirit of brainstorming are that we could add a quirks parameter which takes a flag instead of a bool. Or we could add a quirks flag to the scmi_protocol_handle struct. regards, dan carpenter
On Wed, Feb 26, 2025 at 12:31:27PM +0300, Dan Carpenter wrote: > On Wed, Feb 26, 2025 at 09:55:21AM +0100, Johan Hovold wrote: > > On Wed, Feb 26, 2025 at 09:12:23AM +0100, Johan Hovold wrote: > > > On Wed, Feb 26, 2025 at 08:13:38AM +0530, Sibi Sankar wrote: > > > > > > scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, > > > > u8 describe_id, u32 message_id, u32 valid_size, > > > > u32 domain, void __iomem **p_addr, > > > > - struct scmi_fc_db_info **p_db, u32 *rate_limit) > > > > + struct scmi_fc_db_info **p_db, u32 *rate_limit, > > > > + bool skip_check) > > > > > > This does not look like it will scale. > > > > After taking a closer look, perhaps it needs to be done along these > > lines. > > > > But calling the parameter 'force' or similar as Dan suggested should > > make it more readable. > > > > > > { > > > > int ret; > > > > u32 flags; > > > > @@ -1919,7 +1920,7 @@ scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, > > > > > > > > /* Check if the MSG_ID supports fastchannel */ > > > > ret = scmi_protocol_msg_check(ph, message_id, &attributes); > > > > - if (!ret && !MSG_SUPPORTS_FASTCHANNEL(attributes)) > > > > + if (!ret && !MSG_SUPPORTS_FASTCHANNEL(attributes) && !skip_check) > > > > > > Why can't you just make sure that the bit is set in attributes as I > > > suggested? That seems like it should allow for a minimal implementation > > > of this. > > > > My idea here was that you could come up with some way of abstracting > > this so that you did not have to update every call site. Not sure how > > feasible that is. > > I'm having a hard time finding your email. https://lore.kernel.org/lkml/Z4Dt8E7C6upVtEGV@hovoldconsulting.com/ > Why does the scmi_proto_helpers_ops struct even exist? We could just > call all these functions directly. Do we have plans to actually create > different implementations? > > If we got rid of the scmi_proto_helpers_ops struct then we could just > rename scmi_common_fastchannel_init() to __scmi_common_fastchannel_init() > and create a default wrapper around it and a _forced() wrapper. > > Some other potentially stupid ideas in the spirit of brainstorming are > that we could add a quirks parameter which takes a flag instead of a > bool. Or we could add a quirks flag to the scmi_protocol_handle struct. Something like that, yes. :) I didn't try to implement it, but it seems like it should be possible implement this is a way that keeps the quirk handling isolated. Johan
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 9313b9020fc1..b182fa8e8ccb 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -1903,7 +1903,8 @@ static void scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, u8 describe_id, u32 message_id, u32 valid_size, u32 domain, void __iomem **p_addr, - struct scmi_fc_db_info **p_db, u32 *rate_limit) + struct scmi_fc_db_info **p_db, u32 *rate_limit, + bool skip_check) { int ret; u32 flags; @@ -1919,7 +1920,7 @@ scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, /* Check if the MSG_ID supports fastchannel */ ret = scmi_protocol_msg_check(ph, message_id, &attributes); - if (!ret && !MSG_SUPPORTS_FASTCHANNEL(attributes)) + if (!ret && !MSG_SUPPORTS_FASTCHANNEL(attributes) && !skip_check) return; if (!p_addr) { diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c index c7e5a34b254b..5b4559d0b054 100644 --- a/drivers/firmware/arm_scmi/perf.c +++ b/drivers/firmware/arm_scmi/perf.c @@ -48,6 +48,10 @@ enum { PERF_FC_MAX, }; +enum { + PERF_QUIRK_SKIP_FASTCHANNEL_LEVEL_GET, +}; + struct scmi_opp { u32 perf; u32 power; @@ -183,6 +187,7 @@ struct scmi_perf_info { enum scmi_power_scale power_scale; u64 stats_addr; u32 stats_size; + u32 quirks; bool notify_lvl_cmd; bool notify_lim_cmd; struct perf_dom_info *dom_info; @@ -838,9 +843,10 @@ static int scmi_perf_level_limits_notify(const struct scmi_protocol_handle *ph, } static void scmi_perf_domain_init_fc(const struct scmi_protocol_handle *ph, - struct perf_dom_info *dom) + struct perf_dom_info *dom, u32 quirks) { struct scmi_fc_info *fc; + bool quirk_level_get = !!(quirks & BIT(PERF_QUIRK_SKIP_FASTCHANNEL_LEVEL_GET)); fc = devm_kcalloc(ph->dev, PERF_FC_MAX, sizeof(*fc), GFP_KERNEL); if (!fc) @@ -849,26 +855,26 @@ static void scmi_perf_domain_init_fc(const struct scmi_protocol_handle *ph, ph->hops->fastchannel_init(ph, PERF_DESCRIBE_FASTCHANNEL, PERF_LEVEL_GET, 4, dom->id, &fc[PERF_FC_LEVEL].get_addr, NULL, - &fc[PERF_FC_LEVEL].rate_limit); + &fc[PERF_FC_LEVEL].rate_limit, quirk_level_get); ph->hops->fastchannel_init(ph, PERF_DESCRIBE_FASTCHANNEL, PERF_LIMITS_GET, 8, dom->id, &fc[PERF_FC_LIMIT].get_addr, NULL, - &fc[PERF_FC_LIMIT].rate_limit); + &fc[PERF_FC_LIMIT].rate_limit, false); if (dom->info.set_perf) ph->hops->fastchannel_init(ph, PERF_DESCRIBE_FASTCHANNEL, PERF_LEVEL_SET, 4, dom->id, &fc[PERF_FC_LEVEL].set_addr, &fc[PERF_FC_LEVEL].set_db, - &fc[PERF_FC_LEVEL].rate_limit); + &fc[PERF_FC_LEVEL].rate_limit, false); if (dom->set_limits) ph->hops->fastchannel_init(ph, PERF_DESCRIBE_FASTCHANNEL, PERF_LIMITS_SET, 8, dom->id, &fc[PERF_FC_LIMIT].set_addr, &fc[PERF_FC_LIMIT].set_db, - &fc[PERF_FC_LIMIT].rate_limit); + &fc[PERF_FC_LIMIT].rate_limit, false); dom->fc_info = fc; } @@ -1282,6 +1288,7 @@ static int scmi_perf_protocol_init(const struct scmi_protocol_handle *ph) { int domain, ret; u32 version; + struct device_node *np; struct scmi_perf_info *pinfo; ret = ph->xops->version_get(ph, &version); @@ -1297,6 +1304,17 @@ static int scmi_perf_protocol_init(const struct scmi_protocol_handle *ph) pinfo->version = version; + /* + * Some X1E devices support fastchannel for LEVEL_GET but erroneously + * says otherwise in the protocol message attributes. Add a quirk to + * force fastchannel on LEVEL_GET to prevent crashes on such devices. + */ + np = of_find_compatible_node(NULL, NULL, "qcom,x1e80100"); + if (np) { + pinfo->quirks = BIT(PERF_QUIRK_SKIP_FASTCHANNEL_LEVEL_GET); + of_node_put(np); + } + ret = scmi_perf_attributes_get(ph, pinfo); if (ret) return ret; @@ -1315,7 +1333,7 @@ static int scmi_perf_protocol_init(const struct scmi_protocol_handle *ph) scmi_perf_describe_levels_get(ph, dom, version); if (dom->perf_fastchannels) - scmi_perf_domain_init_fc(ph, dom); + scmi_perf_domain_init_fc(ph, dom, pinfo->quirks); } ret = devm_add_action_or_reset(ph->dev, scmi_perf_xa_destroy, pinfo); diff --git a/drivers/firmware/arm_scmi/powercap.c b/drivers/firmware/arm_scmi/powercap.c index 1fa79bba492e..90e92fc432e3 100644 --- a/drivers/firmware/arm_scmi/powercap.c +++ b/drivers/firmware/arm_scmi/powercap.c @@ -720,23 +720,23 @@ static void scmi_powercap_domain_init_fc(const struct scmi_protocol_handle *ph, POWERCAP_CAP_SET, 4, domain, &fc[POWERCAP_FC_CAP].set_addr, &fc[POWERCAP_FC_CAP].set_db, - &fc[POWERCAP_FC_CAP].rate_limit); + &fc[POWERCAP_FC_CAP].rate_limit, false); ph->hops->fastchannel_init(ph, POWERCAP_DESCRIBE_FASTCHANNEL, POWERCAP_CAP_GET, 4, domain, &fc[POWERCAP_FC_CAP].get_addr, NULL, - &fc[POWERCAP_FC_CAP].rate_limit); + &fc[POWERCAP_FC_CAP].rate_limit, false); ph->hops->fastchannel_init(ph, POWERCAP_DESCRIBE_FASTCHANNEL, POWERCAP_PAI_SET, 4, domain, &fc[POWERCAP_FC_PAI].set_addr, &fc[POWERCAP_FC_PAI].set_db, - &fc[POWERCAP_FC_PAI].rate_limit); + &fc[POWERCAP_FC_PAI].rate_limit, false); ph->hops->fastchannel_init(ph, POWERCAP_DESCRIBE_FASTCHANNEL, POWERCAP_PAI_GET, 4, domain, &fc[POWERCAP_FC_PAI].get_addr, NULL, - &fc[POWERCAP_FC_PAI].rate_limit); + &fc[POWERCAP_FC_PAI].rate_limit, false); *p_fc = fc; } diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h index d62c4469d1fd..fe4c724caba3 100644 --- a/drivers/firmware/arm_scmi/protocols.h +++ b/drivers/firmware/arm_scmi/protocols.h @@ -280,7 +280,7 @@ struct scmi_proto_helpers_ops { u32 valid_size, u32 domain, void __iomem **p_addr, struct scmi_fc_db_info **p_db, - u32 *rate_limit); + u32 *rate_limit, bool skip_check); void (*fastchannel_db_ring)(struct scmi_fc_db_info *db); int (*get_max_msg_size)(const struct scmi_protocol_handle *ph); };
The addition of per message-id fastchannel support check exposed a SCP firmware bug which leads to a device crash on X1E platforms. The X1E firmware supports fastchannel on LEVEL_GET but fails to have this set in the protocol message attributes and the fallback to regular messaging leads to a device crash since that implementation has a bug for all the X1E devices in the wild. Fix this by introducing a quirk that selectively skips the per message-id fastchannel check only for the LEVEL_GET message on X1E platforms. Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com> --- drivers/firmware/arm_scmi/driver.c | 5 +++-- drivers/firmware/arm_scmi/perf.c | 30 +++++++++++++++++++++------ drivers/firmware/arm_scmi/powercap.c | 8 +++---- drivers/firmware/arm_scmi/protocols.h | 2 +- 4 files changed, 32 insertions(+), 13 deletions(-)